Renault managing director Cyril Abiteboul admits there were conversations between the French manufacturer and McLaren over a power unit supply, but that the situation is now "very quiet".

McLaren has been assessing its options for 2018, having been frustrated by a lack of progress with current partner Honda. Attempts to secure a Mercedes deal fell through after talks earlier this season, leaving Renault as the only realistic alternative for the team. Abiteboul confirmed there had been talks with McLaren, but suggested there would only have been a chance to agree a deal if it was no longer supplying one of its current teams.

"The situation is that we have a multi-year contracts with Red Bull Racing and Toro Rosso," Abiteboul said. "Frankly, we are open to discussions.

"I can confirm that there have been discussions with McLaren. As you mentioned, there is a restriction in the regulations if we wanted to supply more than three teams. Any addition to that, I don't think that it would be reasonable to believe that we could supply more than three without degrading the level of service and the quality of service for the other teams.

"We've had discussions. Frankly, we have a contract in place. We value the relationship with Red Bull. It's a long-standing relationship, and we would like to carry this relationship until its term, 2020. But you know, if there is something to be done, why not? But right now, I understand that things are very quiet."

The opportunity had opened up due to Toro Rosso and Honda holding initial talks about a potential supply for 2018, but no deal was agreed. With Honda bringing an upgraded power unit to the Belgian Grand Prix for McLaren, executive director Zak Brown said the progress had still not been as significant as he wished.

"We haven't been satisfied with things all year but I think Hasegawa-san has not been satisfied with how things have gone," Brown said. "So we have seen some improvements here at Spa, not to the level that we had hoped for, but some improvement nonetheless."

And Honda's head of F1 project Yusuke Hasegawa admitted that the Spa upgrade has not been as complete as the Japanese manufacturer had been targeting.

"Actually we planned to introduce the spec four engine here, but we failed and didn't match to the schedule," he said. "We have half of the upgrade, so we called it 3.5 and 3.6. But I thought we could introduce some decent upgrades here, so we didn't stop implementing the upgrade."